   // 旋转数组
   let arr = [1, 2, 3, 4, 5, 6]
   // 旋转k步
   function xuanzhuan (arr, k) {
     let arr1 = []
     let yu = k % arr.length
     let left = arr.splice(0, arr.length - yu)
     let right = arr
     return [...right, ...left]
   }
   console.log(xuanzhuan(arr, 8));
